Enginelight comes on and tranmission jerks at shifting

You need to replace the "B" shift solenoid inside the transmission.

Stop any oil leaks as the transmission requires exacting oil pressure to do the job. Any leaks reduces the pressure so gear changing is affected. Besides when do you know if the oil level has dropped below operating level and will be insufficient for the gear box.

Possible TPS (Throttle Posision sensor)

a DTC reader is the only answer

you need to have the engine codes pulled in the us auto zone and advance do it for free.this is the only way to know what is happening.

I would suggest you take back to the VW dealer - don't they give a guarantee for work they do?

Sounds to me that you need to have your clutch replaced, it sounds like you have either broken teeth on the flywheel gear or bent or broken fingers on your clutch plate...
Hope this helps!
Happy Holidays!

torque and pump causing noise and jerking is where fluid pressure is being lost,mine had same problem

check the vacuum line.

on top of the tranmission there will be wires that make the tranmission shift, check and see if they are loose or brokes, if that doesnt work try useing lucus for tranmissions, it is very effective